ISO 24551:2019

This document specifies ergonomic requirements and recommendations for consumer product spoken instructions that are provided to guide users in the operation of a product and/or as a means of providing feedback to users about the status/state of a product. Such instructions can be used by persons with or without visual impairments, and are useful for users who have difficulty reading and/or cognitive impairments. The applicability of the requirements and recommendations described in this document does not depend on the language of the instructions or whether the instructions are provided via recorded human speech or synthesized speech from text. The requirements and recommendations in this document are applicable to conventional, stand-alone consumer products in general, whose function is limited by characteristics that prevent a user from attaching, installing or using assistive technology in order to use the product. They are not applicable to machines and equipment used for professional work. This document does not apply to products for which the instructional content and/or the means of presentation are specified in other standards (e.g. medical devices, fire alarms). It also does not provide recommendations or requirements for spoken instructions of Interactive Voice Response (IVR) systems or digital assistants on personal computers or similar devices. NOTE ISO 9241‑154 provides recommendations or requirements for IVR systems. This document does not specify voice sounds of text-to-speech systems or narrative speech used in place of printed instruction manuals and independently from the product.